Download FreeRTOS
 

Quality RTOS & Embedded Software

KERNEL
WHAT'S NEW
FreeRTOS website now available in Simplified Chinese
Search and browse content in your preferred language. See the blog post.
New FreeRTOS Long Term Support version now available.
Receive security patches and critical bug fixes on FreeRTOS libraries for two years. See the blog post.
FreeRTOS Extended Maintenance Program (EMP) registration now open.
Providing security patches and critical bug fixes on FreeRTOS Long Term Support (LTS) versions for up to 10 additional years. See the blog post.
FreeRTOS-Plus-TCP v3.0.0 released:
We've added comprehensive unit tests and penetration and protocol testing. See the blog post.
Featured FreeRTOS IoT Integrations:
Introducing three featured integrations for more secure IoT applications. See the blog post.

Co-routines
[More about co-routines...]

Co-Routine States

Co-routines are only intended for use on very small processors that have severe RAM constraints, and would not normally be used on 32-bit microcontrollers.

A co-routine can exist in one of the following states:

  • Running

    When a co-routine is actually executing it is said to be in the Running state. It is currently utilising the processor.

  • Ready

    Ready co-routines are those that are able to execute (they are not blocked) but are not currently executing. A co-routine may be in the Ready state because:

    1. Another co-routine of equal or higher priority is already in the Running state, or
    2. A task is in the Running state - this can only be the case if the application uses both tasks and co-routines.

  • Blocked

    A co-routine is said to be in the Blocked state if it is currently waiting for either a temporal or external event. For example, if a co-routine calls crDELAY() it will block (be placed into the Blocked state) until the delay period has expired - a temporal event. Blocked co-routines are not available for scheduling.

There is currently no co-routine equivalent to a tasks Suspended state.

Valid co-routine state transitions
Copyright (C) Amazon Web Services, Inc. or its affiliates. All rights reserved.